package com.shuang.graph18;

import java.util.*;
 
public class Main {
    // 基于Bellman_ford-SPFA方法（队列优化）
    // Define an inner class Edge
    static class Edge {
        int from;
        int to;
        int val;
        public Edge(int from, int to, int val) {
            this.from = from;
            this.to = to;
            this.val = val;
        }
    }
 
    public static void main(String[] args) {
        // Input processing
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        List<List<Edge>> graph = new ArrayList<>();
 
        for (int i = 0; i <= n; i++) {
            graph.add(new ArrayList<>());
        }
 
        for (int i = 0; i < m; i++) {
            int from = sc.nextInt();
            int to = sc.nextInt();
            int val = sc.nextInt();
            graph.get(from).add(new Edge(from, to, val));
        }
 
        // Declare the minDist array to record the minimum distance form current node to the original node
        int[] minDist = new int[n + 1];
        Arrays.fill(minDist, Integer.MAX_VALUE);
        minDist[1] = 0;
 
        // Declare a queue to store the updated nodes instead of traversing all nodes each loop for more efficiency
        Queue<Integer> queue = new LinkedList<>();
        queue.offer(1);
 
        // Declare an array to record the times each node has been offered in the queue
        int[] count = new int[n + 1];
        count[1]++;
 
        // Declare a boolean array to record if the current node is in the queue to optimise the processing
        boolean[] isInQueue = new boolean[n + 1];
 
        // Declare a boolean value to check if there is a negative weight loop inside the graph
        boolean flag = false;
 
        while (!queue.isEmpty()) {
            int curNode = queue.poll();
            isInQueue[curNode] = false; // Represents the current node is not in the queue after being polled
            for (Edge edge : graph.get(curNode)) {
                if (minDist[edge.to] > minDist[edge.from] + edge.val) { // Start relaxing the edge
                    minDist[edge.to] = minDist[edge.from] + edge.val;
                    if (!isInQueue[edge.to]) { // Don't add the node if it's already in the queue
                        queue.offer(edge.to);
                        count[edge.to]++;
                        isInQueue[edge.to] = true;
                    }
 
                    if (count[edge.to] == n) { // If some node has been offered in the queue more than n-1 times
                        flag = true;
                        while (!queue.isEmpty()) queue.poll();
                        break;
                    }
                }
            }
        }
 
        if (flag) {
            System.out.println("circle");
        } else if (minDist[n] == Integer.MAX_VALUE) {
            System.out.println("unconnected");
        } else {
            System.out.println(minDist[n]);
        }
    }
}